218 FLORA INDTCA. and are hence gradually drying up. This diminution of many of the lakes is 'no doubt entirely attributable to a change of climate, which is extremely interesting in a botanical point of view, from its favouring the immigration of many saline types of the Caspian flora. Where the surface is covered with salt-marshes, are found Glaux maritima, Eurotia, Corispermum, Caroxylon, Su&da, Salsola, Chenopodium, Ambrina, Christolea^ Triglochin; and a large Nostoc, of a species eaten in China, floats on the surface of the pools. The carbonate of soda again appears to have no appreciable effect on the vegetation of the dry soil it en- crusts; grasses, tufted Androsace?, Astragali) Gnaphalia, Ar- temisia, etc., being alike covered with it. Cultivation in Tibet attains the height of 15,000 feet, and is luxuriant below 12,000 feet, barley and wheat being the grains cultivated, with rape and millet at lower levels. The indigenous vegetation is everywhere scanty. Though there is no forest, the banks of the rivers and streams are skirted by a dense scrub of bushes, chiefly Myricaria, Hippophae, Rosa, m&Lonicera. Populus balsamifera and Euphratici, and Juni- perus excelsa are the only trees, and these occur rarely; as does Pinus excelsa^ which is only found towards the confines of Hasora, and can hardly be considered a Tibetan tree. My~ ricaria and Hippophae occasionally attain a height of twenty feet. Of cultivated trees, apricots and Populus balsamifera are seen up to 12,000 feet; apples, walnut, the black poplar, and Elaagnus up to 11,000 feet, pears to 10,000 feet, and grapes and white poplar and plane-trees to 9000 feet. Subtropical types ascend along the course'of the Indus to Bondu and Iskardo, and some of them even as far as 11,000 feet, in Nubra and lie, of which the following genera arc ex- amples :— Capparieu Eehinops. Peganum. Tamarix GMica. Tribulus. Lyciutn. Sophora, Viucctoxicxim.